The present invention relates to mufflers, and particularly to mufflers having multiple-plated outer shells. More particularly, the present invention relates to multiple-plated outer shells having thermal expansion portions that permit the multiple plates of the outer shell to move relative to each other.
The flow of exhaust gas through a muffler having a multiple-plated outer shell causes the outer shell to heat up due to the high temperature of the exhaust gas. Multiple-plated outer shells include an inner plate that is in direct contact with the hot exhaust gas and an outer plate that is insulated from the exhaust gas by the inner plate. This arrangement of the inner and outer plates causes the inner plate to heat up faster than the outer plate. As a result, the inner plate expands relative to the outer plate. In addition, this arrangement causes the outer plate to cool down faster than the inner plate which results in the outer plate contracting relative to the inner plate. The relative expansion and contraction of the inner and outer plates causes compressive and tensile forces in the inner and outer plates. These compressive and tensile forces are repeated every time the inner plate expands relative to the outer plate. The compressive forces in the inner plate may cause buckling of the inner plate.
An exhaust component is provided having first and second end caps, an inner shell coupled to the first and second end caps, and an outer shell coupled to the first and second end caps. A channel is defined between the inner shell and one of the first and second end caps. A portion of the outer shell is positioned in the channel to move longitudinally through the channel relative to the inner shell. The outer shell includes a notch member that is spaced apart from the inner shell. The notch member configured to change shape to permit the outer shell to move circumferentially relative to the inner shell.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.